Well tubing plug



Dec. 11., 1934. C. OT|S 1,984,230

I lWELL TUBING PLUG Filed ApIil 13, `l932 2 `Sheets-511891l 1 Dec. 11, 1934. ||,v OT|$ 1,984,230

WELL TUBING PLUG Filed April l5, 1932 2 Sheets-Sheet 2 .rgeii Cz Qs Patented Dec. l1, 1934 UNITED STATES PATENT GFFICE WELL TUBING PLUG Herbert ,.C. Otis, Shreveport, La. Applidafion April 13, 19325 Serial N0. 605,050

10 Claims. (Cl. 166-13) This invention relates to a plug for well wardly facing tapering shoulder 17 so that the tubings, and more particularly to an apparatus plug constitutes a valve for co-action with the for use in plugging the tubing of wells while tapering seat. The upper end ofthe plug has running the same into the well against the flowembedded therein a pin 18 projecting above 5 ing pressures existing therein. the upper end of the plug, the purpose of which 5 n An important object of the invention is, the will. presently appear. Bull plug 13 and the provision of a device of this character which, coupling 19 connecting the bull plug to the after the tubing has been fully installed, may screen are preferably provided with perforations be opened from the upper end of the well tubing 20, the purpose of which will presently appear.

l and Without depending upon the introduction In installing the tubing employing plugging 10 to the well of any material which might submeans of the type described, the plug is loosely sequently interfere with operation thereof. held against the seat in any suitable manner A still further object of the invention is the as suggested in Figs. 1 and 2, While tubing is production of an apparatus of this character run in the upper end ofthe casing to and l which, after having been opened, may be readily slightly below a point where the casing may be l5 closed at any time in order that ilow through sealed thereto. In Fig. 1, I have shown the the tubing may be discontinued or the pressures upper end of the casing as provided with upper generated in the well employed to assist in and lower ram gates 21 and 22 and the tubing elevating the tubing during removal thereof. as having been inserted so that it extends zo A still further object of the invention is the through the upper lram gate which is in sealing provision in apparatus of this character of a engagement therewith. construction such that the plug, when moved It will be obvious that at this time the presto its inoperative position, in no manner inters ure Within the well will build up against the feres with normal operation of the well. plug 16 holding the same in sealing engage- ?.5 These and other objects I attain by the conment with the seat of nipple 14 so that the 25 struction shown in the accompanying drawings, holding means C provided for the plug during wherein, for the purpose of illustration, I have installation of the tubing to this extent may shown a preferred embodiment of my invention now be released. The tubing is then run to and wherein: the desired depth, the well pressure maintain- Fig. 1 is a side elevation partially in section ing the plug against its seat, after which the 30 illustrating the rst step in installation of tubing tubing may be sealed to the casing in the usual employing a plug constructed in accordance with manner generally illustrated in Fig. 3. To unmy invention; seat the plug I preferably provide a' connection Fig. 2 is an enlarged detail sectional view 23'between the well casing 10 and the tubing showing the manner in which the plug is held 11 so that the casing pressure may be intro- 35 against its Seat; duced to the tubing above plug 16. VWhen the Fig. 3 is an enlarged detail sectional view pressure within the tubing equals that within' showing the complete installation and also i1- the casing it will be obvious that the plus will lustrating the mllnting 0f fishing S001 Control still remain seated, for the exposed area ofthe 40 and Dackel' for use in reseatng the P1118; and plug within the tubing is less than that subject#- 40 Fist 4 iS an enlargd Sectional View SllOWiIlg` ed. to casing pressures. e In order to obtain the a suitable fishing tool. v relative increase in pressure necessary to un- Referrng 110W more particularly t0 the @mW- seating of the plug, the casing valves lmay be ings, the numeral l0 designates a well casing opened to reduce the pressure Within the casand 11 an interirly -dSpOSed tubing, Which ing, or prior to introduction of casing pres- 45 tubing, aS iS usual, iS, Sealed t0 the Casing at its sures a suitable column of Iluid may be introuppel end and iS provided at its 10We1` end With duced to the tubing as through valve 24 so that a screen 12 closed 'at its lower end by a bull when casing pressures are introduced to the plus 13. In accordance with my invention, the tubing the pressure upon the upper surface of 5o upper end 0f the Screen 12 iS Connected with the the p1ug will overbalance that against the low- 50 'tubing 11 hlOllgh a restricted nipple 14, the er surface thereof .and cause the same to be lower end of which is formed with a downunseated. The plug when unseated drops into wardly facing tapering seat 15. For co-action the bull plug where it is maintained in a verwith this seat I provide a plug 16 which may be tical position with the pin 18 accessible, openformed of any suitable material having an upings 20 serving to prevent collection of sand,`

or other foreign substances which would interfere with engagement of this pin, by a suitable fishing tool.

If at any time it becomes desirable to again plug the tubing, it is simply necessary that a fishing tool be run into the well through one of the conventional fishing tool fitting apparatuses such as indicated at 25 and be employed to lift the plug until it engages the seat. The tool should be of the friction type so that a release may be effected when the plug has been seated. One suitable for use in this connection is sectionally illustrated in Fig. 4, wherein 26 indicates the body of the tool having a bore 27 for the reception of pin 18, said bore having its lower end formed with a guiding mouth 28 and having in one wall thereof an opening 29 in which is mounted a'heavy leaf spring 30 to engage the pin and force it into frictional engagement with the wall of bore`27. As indicated,the wall of the bore may be roughened, as for example by threading, so that the frictional grip between the pin and the tool will be increased. This illustration is purely arbitrary as, obviously, there are numbers of fishing tools which might be employed in this capacity.

Since the construction illustrated is capable of considerable modication without any departure from the spirit of my invention, I do not wish to be understood as limiting myself thereto except as hereinafter claimed.

I claim:

y 1. The combination with well tubing and a screen, of means connecting the screen and the lower end of the tubing including a downwardly facing valve seat, a valve plug engaging said seat, said plug being freely movable from said valve seat to a position below the screen.

2. The combination with Well tubing and a screen, of means connecting the screen and the lower end of the tubing including a downwardly facing valve seat, a valve plug engaging said seat, said plug being freely movable from said valve seat to a position below the screen, and means at the lower end of the screen receiving said plug when separated from its seat.

3. 'Ihe combinationwith well tubing and a screen, of means connecting the screen and the lower end of the tubing including a downwardly facing valve seat, a valve plug engaging said seat, said plug being freely movable from said valve seat to a position below the screen, means at the lower end`of the screen receiving said plug when separated .from its seat, and means on the upper end of the plug for engagement with a fishing tool by which the plug may be returried to its seat.

4. The combination with a tubing having a scree at the lower end thereof, of an inert means sealing the lower end of the tubing, said means being freely displaceable from the lower end of the tubing by pressures generated within the tubing, and being freely movable from the lower end of the tubing to a point below the screen.

5. The combination with well tubing and a screen, of means connecting the screen and the lower end of the tubing including a downwardly facing valve seat, a valve plug engaging said seat, said plug being freely movable 'from said valve seat to a point below the screen, and means on the upper end of the plug for engagement with a fishing tool by which the plug may be returned to its seat.

6. The combination with a well tubing having a screen at its lower end, of means providing a downwardly facing valve seat at the interior of the tubing immediately above the screen, a valve plug engaging said seat, said plug being adapted to move from the seat by gravity and to be held in engagement therewith by pressures exterior to the tubing, and means at the upper end of the plug for engagement with a fishing tool by which the plug may be returned to its seat.

7. The combination with a' well tubing having a screen at its lower end, of means providing a downwardly facing valve seat at the interior of the tubing immediately above the screen, a valve plug engaging said seat, said plug being adapted to move from the seat by gravity and to be held in engagement therewith by pressures exterior to the tubing, and means in spaced relation to said seat and beneath said screen to receive and support the. plug when separated from its seat.

8. The combination with a well tubing having a screen at its lower end, of means providing a downwardly facing valve seat at the interior of the tubing immediately above the screen, a valve plug engaging-said seat, said plug being adapted to move from the seat by gravity and to be held in engagement therewith by pressures exterior to the tubing, means at the upper end of the plug for engagement with a fishing tool by which the plug may be returned to its seat, and means in spaced relation to said seat and beneath said screen to receive and support the plug when separated from its seat.

9. The combination with a well tubing having an inlet at its lower end, of means providing a downwardly facing valve seat at the interior of the tubing, a valve plug engaging said seat, said plug being held in engagement with the seat by pressures exterior to the tubing and when unseated moving by gravity to a point disposed below the current of iiuid entering the inlet whereby said fluid will not reseat the plug.

10. In a well, the combination of a casing, a

tubing within the casing and sealed to the cas-Y ing at the upper end of the casing, a controllable connection between the casing and tubing and a closure valve for the lower end of the tubing maintained in engagement with the lower end of the tubing by casing pressures alone, said valve when unseated moving by gravity to a position from which it is unreseatable by fluids entering the tubing.

HERBERT C. OTIS. 

